Twelve-year experience with glutaraldehyde-preserved porcine xenografts

Three hundred fifty-two patients underwent aortic (AVR) or mitral (MVR) valve replacement with a glutaraldehyde-preserved porcine xenograft from 1970 to 1980. Analysis of this series revealed the following information: hospital mortality, 11.6% (41/352); late mortality, 5.5% per patient-year (60/1,090.7); actuarial 5 year survival rate, 70%; incidence of thromboembolism and hemorrhage, 1.4% per patient-year (15/1,090.7); incidence of spontaneous degeneration, 1.1% per patient-year (12/1,090.7); and transvalvular gradient. AVR 16 mm Hg and MVR 4.6 mm Hg. These results compare favorably with results from other porcine xenograft series and with those reported for prosthetic valves. There is no apparent difference in the type of xenograft used with the exception that spontaneous degeneration occurred less frequently in mitral valves that had not undergone pressure fixation than in those that had. The use of flexible stents improved the ease of valve implantation but did not affect leaflet durability as anticipated. Calcification occurred randomly with no relationship to time of implantation. Reoperation was for spontaneous valve deterioration by calcification or collagen degeneration in 11 cases, paravalvular leak in 13 cases, and implantation of an undersized valve in four cases; there was one reoperation for infection. Results support the continued use of porcine xenografts and suggest that improved manufacturing techniques will reduce the incidence of spontaneous, sterile deterioration, which is the only serious drawback to routine use of the porcine xenograft.